  .nav-tab-bar {
      width: 100vw;
      max-width: 750px;/*no*/
      position: fixed;
      left: 50%;
      bottom: 0;
      transform: translate(-50%, 0);

      .am-tab-bar-bar {
          height: 90px;/*rem*/
      }
      .nav-img {
        width: 130px;/*rem*/
        height: 100px;/*rem*/
      }
  }